Dr. Jeff Hersh: Can microwave popcorn cause lung disease?

Wednesday

Mar 19, 2014 at 8:22 PMMar 19, 2014 at 8:22 PM

By Dr. Jeff HershMore Content Now

Q: I read that there is a lung disease that usually occurs in lung transplant patients but that you can also get from microwave popcorn. Is this real?A: Inhaled air (whether through the nose, mouth or directly through the trachea in people who have had a tracheostomy) travels through the trachea (the windpipe) then splits to go to either the left or right main bronchi to get to the left or right lung, respectively, then on to the bronchioles and finally to the alveoli (the air sacs where oxygen is delivered to the blood and carbon dioxide taken away).The condition you are describing is bronchiolitis obliterans (BO); patients with this condition have their bronchioles narrowed by scar tissue (fibrosis) and inflammation, which obstructs the flow of air in and out of the lungs.Mild BO often does not cause any symptoms (and hence may be undiagnosed), however if it is more severe the patient will experience shortness of breath with exertion (this can even occur at rest if the condition progresses and becomes very severe), a dry cough and/or wheezing, symptoms similar to those that occur in COPD and asthma patients. Hence the initial evaluation and treatments are often to address the possibility of these other conditions since they are much more common.In the general population BO is uncommon (it is the diagnosis in only 5 of every 100,000 hospital admissions), although there are many possible causes. These include:- infections, including viruses such as respiratory syncytial virus (typically in infants), adenovirus and others;- inflammatory disorders, including autoimmune diseases such as lupus, rheumatoid arthritis and others;- drug reactions, such as those that may occur to some chemotherapy agents or from aspiration of activated charcoal (sometimes used in emergency situations to prevent absorption after potentially toxic ingestions);- exposure to toxins, including industrial (or other) exposure to sulfur dioxide, ammonia, diacetyl or many others; inhalation of toxins from burn pits (such as may occur when garbage is burned by our troops in Afghanistan or Iraq); exposure to mustard gas or many other toxic exposures.In 2000, the Missouri Department of Health became suspicious of a possible link between BO and inhalation of diacetyl by employees in a microwave popcorn factory (this chemical was used to produce the artificial butter flavor), which was confirmed in a report by the National Institute for Occupational Safety and Health in 2004. Since 2007 there have been cases of BO felt to be caused by inhalation of diacetyl in consumers who frequently ate microwave popcorn (and hence inhaled large cumulative amounts of diacetyl). Diacetyl is no longer used as an ingredient in microwave popcorn flavorings by most manufacturers.However, BO is very common in people who have had a lung transplant, affecting up to half of these patients by five years after their transplant and three-quarters by 10 years.Patients suspected of having BO will have their lung function tested (as would be done to evaluate many cases of shortness of breath); the results would show a decrease in how much air they can forcefully exhale (a decreased forced expiratory volume). Imaging of the lungs will include chest X-rays and a high resolution CT scan. Finally, the definitive diagnosis is confirmed by evaluation of a biopsy specimen (often obtained by a bronchoscopy).In lung transplant patients, antibiotics and immune suppressants (if an immune reaction to the transplanted lung is suspected as a contributing factor) may be utilized. In cases where inflammation is the main pathological feature, high-dose steroid medications or other anti-inflammatory medicines may be used. For patients with severe respiratory compromise, lung transplantation may be the best treatment option.If you develop shortness of breath you should see your healthcare provider to be evaluated. More common causes will be suspected first; however, it is important to give your doctor a complete history of your symptoms as well as your risk factors so they can do a complete and thorough evaluation.Jeff Hersh, Ph.D., M.D., can be reached at DrHersh@juno.com.

Never miss a story

Choose the plan that's right for you.
Digital access or digital and print delivery.